Critically ill patients often require life support in the form of mechanical ventilation. Ventilated patients receive an artificial airway in the form of an Endotracheal Tube or Tracheostomy Tube. The artificial airway is placed in the trachea and a distal cuff is inflated to seal the trachea to receive mechanical ventilation. The artificial airway cuff is placed just below the vocal cords and the glottis. It has been known that patients on mechanical ventilation are at increased risk of developing Ventilator Associated Pneumonia (VAP). Recent studies have shown reductions in the incidence of VAP when artificial airways that incorporate an aspiration tube are employed. Use of these newer artificial airways reduce the incidence of VAP and delay onset of VAP, but improvement is still required. Additionally, the artificial airway is an imperfect barrier to bacteria colonies that inhabit the mouth, throat and stomach, and interrupts the body's natural defense mechanism. Methods that at least partially restore the natural action of expectoration are expected to improve care.
Subglottic secretions that are encountered in the airway can be very thick and persistent and present a challenge for removal via the conventional passages in the artificial airways. Adding additional lumens to artificial airways is not practical, because concern exists over the available space in the patient's throat.